관성센서를 이용한 농용 무인 헬리콥터의 자세 추정

배영환,오민석,구영모,Bae, Yeonghwan,Oh, Minseok,Koo, Young Mo 경북대학교 농업과학기술연구소 2014 慶北大農學誌 Vol.32 No.3

본 논문에서는 저가의 MEMS 관성 센서와 지자기 센서를 이용하여 자세 정보를 제공받는 자세측정장치(ARHS)를 구현하였다. 저가형 IMU센서와 MCU를 이용하여 운동 자세각을 계산하는 DCM 알고리즘을 설계하고, 3축짐벌에 장착하여 연산결과의 정확도를 측정하였다. DCM 알고리즘을 이용 연산된 자세각의 정확도는 roll 및 pitch에 대하여 약 1.1%로 나타났으며, yaw각의 경우는 3.7%로 나타났다. Yaw 각의 경우에는 스텝핑 모터를 구동하는 실험환경에 따른 교란의 영향으로 그 오차가 상대적으로 크게 나타난 것으로 평가되었다. 짐벌 실험장치를 이용한 센서의 검증에서 더욱 정밀한 실험을 위해서는 주변 환경 요인에 대한 제어가 요구될 것으로 보이며, 실험장치의 스테핑 모터 구동 시 발생하는 진동 및 자기장의 영향과 실험 장치의 금속성 구조물의 영향으로 생각되는 센서 데이터의 오차 및 불안정 상태를 차단할 수 있는 장치의 보완이 필요할 것으로 보인다. 그리고 지자기 센서의 경우 좁은 범위의 측정에 추가하여 넓은 범위의 측정도 보완되어야 할 것으로 생각된다. Agricultural unmanned helicopters have become a new paradigm for aerial application. Yet, such agricultural helicopters require easy and affordable attitude control systems. Therefore, this study presents an affordable attitude measurement system using a DCM (direction cosine matrix) algorithm that would be applied to agricultural unmanned helicopters. An IMU using a low-cost MEMS and an algorithm to estimate the attitude of the helicopter were applied in a gimbals structure to evaluate the accuracy of the attitude measurements. The estimation errors in the attitude were determined in comparison with the true angles determined by absolute position encoders. The DCM algorithm and sensors showed an accuracy of about 1.1% for the roll and pitch angle estimation. However, the accuracy of the yaw angle estimation at 3.7% was relatively larger. Such errors may be due to the magnetic field of the stepping motor and encoder system. Notwithstanding, since the intrinsic behavior of the agricultural helicopter remains steady, the determination of attitude would be reliable and practical.

Antimicrobial and Deodorization Finishing of Soybean/Cotton Blended Fiber and Chitosan Finishing with Glyoxal

배영환,김동은,이효진,김의화,정용식,홍영기,이승구,Bae, Young-Hwan,Kim, Dong-Eun,Lee, Hyo-Jin,Kim, Eui-Hwa,Jeong, Yong-Sik,Hong, Young-Ki,Lee, Seung-Goo 한국섬유공학회 2008 한국섬유공학회지 Vol.45 No.2

The soybean/cotton blended fabrics were treated with two different commercial finishing agents to enhance the antimicrobial and deodorization activity. Also, we used the polymeric chitosan for improving the antimicrobial functionality. A pad-dry-cure process was performed to endow those functionality to the soybean protein fabrics. The treated fabrics by finishing agents have significantly improved antimicrobial and deodorization activity. However the chitosan only treated fabrics show relatively low functionality. Thus, we used the glyoxal as a crosslinking agent to increase the adhesion between the fabric and chitosan. The chitosan treated fabrics with glyoxal have high antimicrobial and deodorization activities as well as improved durability.

농용 무인 헬리콥터의 자세추정을 위한 관성센서의 성능 평가

배영환,오민석,구영모,Bae, Yeonghwan,Oh, Minseok,Koo, Young Mo 경북대학교 농업과학기술연구소 2014 慶北大農學誌 Vol. No.

본 논문에서는 저가, 저전력 및 소형의 IMU를 구성하기 위한 MEMS 관성 센서를 이용하여 자세 정보를 제공받는 ARHES에 위의 센서를 사용하기 위해 자이로 센서 및 가속도센서의 데이터 출력 특성을 검증하여 오차 및 정확도를 분석하였다. 센서 실험을 위하여 진자 실험 장치를 제작하였고, 진자 운동에 대한 센서 데이터를 수집하였다. 이론적인 수식을 유추하여 센서 데이터의 정확성 분석을 위한 기준 값으로 설정하였다. 센서값과 이론값을 비교하면 각속도에서 4.32~5.72%, 가속도에서 x-, z-축 방향에 대하여 각각 3.53~6.74% 및 3.91~4.16%의 오차율을 나타냈다. 진자실험 장치를 이용한 센서 검증에서 무인헬리콥터에 사용될 센서로서 적합한 것으로 평가되었으며 이는 짐벌장치 등을 이용한 자세추정 알고리즘을 구성하는데 기초가 되었다. 또한, 더욱 정밀한 실험을 위해서는 온도 등 주변 환경 요인에 대한 보정이 요구된다. The precision aerial application of agricultural unmanned helicopters has become a new paradigm for small farms with orchards, paddy, and upland fields. The needs of agricultural applications require easy and affordable control systems. Recent developments of MEMS technology based on inertial sensors and high speed DSP have enabled the fabrication of low-cost attitude system. Therefore, this study evaluates inertial MEMS sensors for estimating the attitude of an agricultural unmanned helicopter. The accuracies and errors of gyro and acceleration sensors were verified using a pendulum system. The true motion values were calculated using a theoretical estimation and absolute encoder measurement of the pendulum, and then the sensor output was compared with reference values. When comparing the sensor measurements and true values, the errors were determined to be 4.32~5.72%, 3.53~6.74%, and 3.91~4.16% for the gyro rate and x-, z- accelerations, respectively. Thus, the measurement results confirmed that the inertial sensors are effective for establishing an attitude and heading reference system (AHRES). The sensors would be constructed in gimbals for the estimating and proving attitude measurements in the following paper.

에어 덕트용 PET 니들펀칭 부직포의 제조 및 물성에 관한 연구

배영환,도성준,Bae, Younghwan,Doh, Song Jun 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.4

An air intake duct is an automotive part for transferring outside air to the internal combustion engine where the air and fuel are mixed and consumed. While this part has been primarily made of engineering plastics, many manufacturers are attempting to apply textile nonwovens due to their superior sound absorbing performance and lightweight characteristics. In this paper, we studied the manufacturing process of needle punched nonwoven fabric and analyzed various properties in order to investigate the applicability of textile nonwoven as a material for automobile air intake ducts. The nonwoven web was prepared by opening, mixing and carding PET staple fibers and binder fibers. The web was physically bonded by the needle punching process. In addition, we applied heated air through the nonwoven web to improve the mechanical properties of the needle punched nonwoven fabrics by the thermal bonding of interlocking constituent fibers. The results of the tensile test of the nonwoven demonstrated that the hot air treatment to the needle punched nonwoven decreased the elongation of nonwoven, which significantly affects the processability of the air duct production process. Also, the porous structure of the nonwoven improved the sound absorbtion property compared to normal PP plastic. Therefore, the air intake duct made of PET needle punched nonwoven could contribute to decreasing the noise level inside automobiles.

칼라 센서를 이용한 사과와 토마토의 색상 판정

배영환,주철 ( Y . H . Bae,C . Joo ) 한국농업기계학회 1993 바이오시스템공학 Vol.18 No.4

에타놀 - 석유 혼합연료의 농용석유엔진에의 이용에 관한 연구

배영환,류관희 ( Yeong Hwan Bae,Kwan Hee Ryu ) 한국농업기계학회 1982 바이오시스템공학 Vol.7 No.1

CIFER ^® 를 이용한 무인 헬리콥터의 동특성 분석 (III) - 전달함수 해석 -

배영환,구영모,Bae, Yeong-Hwan,Koo, Young-Mo 한국농업기계학회 2012 바이오시스템공학 Vol.37 No.3

Purpose: Aerial application of chemicals with an agricultural helicopter allows for precise and timely spraying and reduces working labor and pollution. An attitude controller for an agricultural helicopter would be helpful to aerial application operator. The objectives of this paper are to determine the transfer function models and to estimate the handling qualities of a bare-airframe model helicopter. Methods: Transfer functions of a model unmanned helicopter were estimated by using NAVFIT and DERIVID modules of the $CIFER^{(R)}$ program to the time history data of frequency sweep flight tests. Control inputs of the transfer functions were elevator, aileron, rudder and collective pitch stick positions and the outputs were resulting on-axis movements of the fuselage. Results: Minimum realization of the transfer functions for pitch rate output to elevator control input and roll rate output to aileron control input produced second order transfer functions with undamped natural frequencies around 3.0 Hz and damping ratios of 0.139 and 0.530, respectively. The equivalent time delays of the transfer functions ranged from 0.16 to 0.44 second. Sensitivity analysis of the proposed parameters allowed derivation of minimal realization of the transfer functions. Conclusions: Handling quality of the model helicopter was addressed based on the eigenvalues of the transfer functions, corresponding undamped natural frequencies with damping ratios. The equivalent time delays of the lateral-directional motion ranged from 0.16 to 0.44 second, longer than the 0.1 to 0.15 second requirement for well-controlled typical manned aerial vehicles.

CIFER^®를 이용한 무인 헬리콥터의 동특성 분석 (II) - 주파수 응답 해석 -

배영환,구영모,Bae, Yeoung-Hwan,Koo, Young-Mo 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.6

The aerial application using an unmanned helicopter has been already utilized and an attitude controller would be developed to enhance the operational convenience and safety of the operator. For a preliminary study of designing flight controller, a state space model for an RC helicopter would be identified. Frequency sweep flight tests were performed and time history data were acquired in the previous study. In this study, frequency response of the flight test data of a small unmanned helicopter was analyzed by using the CIFER software. The time history flight data consisted of three replications each for collective pitch, aileron, elevator and rudder sweep inputs. A total of 36 frequency responses were obtained for the four control stick inputs and nine outputs including linear velocities and accelerations and angular velocities in 3-axis. The results showed coherence values higher than 0.6 for every primary control inputs and corresponding on-axis outputs for the frequency range from 0.07 to 4 Hz. Also the analysis of conditioned frequency response showed its effectiveness in evaluating cross coupling effects. Based on the results, the dynamic characteristics of the model helicopter can further be analyzed in terms of transfer functions and the undamped natural frequency and damping ratio of each critical mode.

습식 마늘박피 시스템 개발 (IV) - 상업용 시스템의 구조와 성능 -

배영환,양규원,백성기,김정호,장영창,이수희,Bae Y. H.,Yang K. W.,Baik S. K.,Kim J.,Chang Y. C.,Lee S. H. 한국농업기계학회 2005 바이오시스템공학 Vol.30 No.1

There are more than three hundred garlic peeling facilities in Korea and most of them use pressurized air for skin peeling operation. One of the major problems of using air for the peeling operation is the occurrence of excessive bruises on the flesh of peeled garlic which causes easy microbial contamination and shortening of the shelf lift. To reduce the occurrence of bruises during the peeling operation, a new type of garlic peeling system was developed which use pressurized water. In this system, high pressure water jets were used to separate garlic bulbs and to peel the skin of garlic cloves. Six commercial systems of this type had been developed and installed at several locations in Korea. The design and performance of the latest system according to three pressure levels were described in this paper. Peeling efficiency of the system was as high as $64.7\%$ in one cycle of peeling operation by three chambers installed in series. Incorporation of a sorting system based on machine vision and re-circulation of unpeeled and partially-peeled garlic enhanced peeling efficiency by additional $30\%$, resulting in total peeling efficiency of the final products of approximately $95\%$. Peeling capacity of the system was over 400 kg per hour.

왕실 여성의 구개음화 실현 양상 연구 -언간 자료를 중심으로-

배영환 ( Bae Young-hwan ) 한말연구학회 2021 한말연구 Vol.- No.59

This study discussed the realization aspect of palatalization shown in Eongan used by women of royal family. Regarding the Eongan used by women of royal family, there is data of 11 queens from Queen Jangnyeol to Empress SunmyeongHyo, including total 322 cases. They are distributed from the 17th century to the early 20th century. The realization rate of palatalization shown in Eongan used by women of royal family in the Joseon Dynasty was 16.54%, and the total occurrence rate of hypercorrection was 3.30%. Compared to other data, this realization rate is very low, which shows that they were conservative in palatalization. The development process of palatalization in women of royal family could be divided into stage of occurrence, stage of diffusion, and stage of completion, and the middle of the 17th century is the stage of occurrence. In the period of Queen Inseon, the palatalization appeared for the first time. The stage of diffusion of palatalization is the period of Queen Jeongsun during the mid and late 18th century. In case of Queen Jeongsun, the palatalization was evenly realized in native words and Sino-Korean words, and the aspect of hypercorrection was also shown. The stage of completion of palatalization is the period of Empress Myeongseong. The realization rate of palatalization shown in Empress Myeongseong is 71.19%. This aspect is similar to the process of diffusion in men of royal family. The language of royal family must be conservative in the process of diffusion than other data reflecting the central dialect. The language of royal family had a conservative attitude towards palatalization because the negative psychology about southern dialect and palatalization occurred in the middle class was ambivalently reflected. Compared to the diffusion process of palatalization in men of royal family, its difference is the occurrence period of palatalization. Contrary to the men of royal family, Queen Inseon probably experienced palatalization early. What should be paid attention to in relation to the realization aspect of palatalization in Eongan used by women of royal family is the education in royal family. Among the essential education for women of royal family, the writing education could be a factor that slowed down the realization of palatalization.